1. Field of the Invention
The invention relates to a filter cartridge, in particular a suction filter cartridge, according to the preamble of claim 1. The invention also comprises a seat element for such a filter cartridge. The inlet area and the outlet opening of the filter cartridge are arranged at the bottom area of the filter cartridge, which also includes a lateral inlet or outlet in a lower section of the inflow and outflow chamber adjacent to the bottom.
2. Description of Related Art
Suction filter cartridges are used in water vessels of automatic drink dispensers, e.g., for hot drinks, provided with a suction pump, such as e.g., coffee makers etc. The inlet and outlet openings of the suction filter cartridge are located in the bottom area of the otherwise completely enclosed cartridge housing. A seat element is arranged in the water vessel of the device, adjusted to the outlet opening, which may be a separate component or be formed at a water vessel. This seat element has an outlet opening as well, through which the filtered water can flow out of the water vessel. The seat element serves to accept the suction filter cartridge inserted into this seat element.
Due to the fact that the outlet opening of the water vessel is connected to the suction pump of the device, the water to be filtered is suctioned out of the water vessel, passes the filter medium or filter media in the cartridge, and reaches the outlet opening in a filtered state.
Due to the fact that the suction filter cartridge is arranged inside the water vessel of the device the filter cartridge floats when the water vessel is filled. In order to prevent floating and thus a separation of the filter cartridge from the outlet opening of the seat element of the water vessel special fastening means are provided. According to a known solution the suction filter cartridge is screwed onto the seat element. Here it is disadvantageous that suction filter cartridges with an asymmetrical filter housing cannot be screwed into narrow water vessels. Additionally, in deep and narrow water vessels tools are necessary to screw in the cartridge.
Another resolution provides for the suction filter cartridge to be placed onto the seat element and to turn over a clamping element after the insertion in order to fix the suction filter cartridge in its position.
From WO 99/01220 a suction filter cartridge is known, in which the water inlet opening is arranged at the bottom and a pass for water through the filter media is provided in the up-current. Furthermore, a downspout is provided for guiding the water downwards to an extraction connector of the water vessel located at the bottom. Here, the mixture of filter means comprising activated carbon and ion exchangers are floated during operation, counteracting any compression of the filter bed.
The downspout is arranged centrally inside the suction filter cartridge, so that the bottom connector of the suction filter cartridge can also occur centrally. Here, the inlet opening is arranged circularly in the suction filter cartridge.
An axial closing element is necessary to seal the outlet channel from the inlet channel.
The suction filter cartridge comprises at its bottom fixing elements, by which it can be connected to a seat element. Additionally it is necessary, though, that the suction filter cartridge is supported on the lid of the water vessel in order to prevent floating of the suction filter cartridge in a filled water vessel. Here, it may be necessary in deep water vessels to extend the suction filter cartridge at the top, e.g. by a rod.
Such additional securing elements are frequently not arranged correctly, thus the tight seat on the seat element is not ensured.